Multiplex correction circuit



MULTIPLEX CORRECTION CIRCUIT Filed Oct. 4, 1938 F'|e.1. a

mvENToR MAR/r afm-HR P23 65 aibn? ATTORNEY Patented Dec. 9, 1941 UNITED ST 'rss e 12611843V MULTIPLEX connso'rioNcmcuir Mark B. Kerr, Rosebank, Staten Island, N. Y., `assigner to Postal Telegraph-Cable Company (New York), New York, N. Y., a corporation of New York Application October 4, 1938, Serial No. 233,170

(orne- 53) 8 Claims.

My invention relates to a multiplex telegraph arrangement and more particularly to a corrector circuit for such multiplex systems.

In multiplex arrangements it is necessary that the distributors at repeater stations or terminal sets be maintained in rotation substantially in synchronism With the distributor at the sending station. For this reason it is the usual practice to provide some means for correcting the speed of rotation of a distributor in accordance with the received signals and under control of such signals. A number of arrangements for this purpose utilizing a tuning fork for driving a phonic motor or other suitable means have been quite commonly used. In al1 of these systems `a vcorrecting commutator is provided cooperating with the receiving distributor. This commutat'or in general is composed of two conducting segments for each of the segments of the receiving distributor. Alternate ones of these corrector commutator segments are connected to a suitable relay or relays through the common ring of the commutator so as to provide the proper speed or phase control. According to the systems used generally in the prior art it is common practise f.-

to provide a combination of relay or relays and condensers to produce the desired correcting impulses so that the discharge of the condenser may be used to test the phase of the brushes.

In accordance with my invention a corrector circuit similar to that described above is utilized. However, I provide an arrangement in which a single neutral relay may be used for the purpose of producing the impulses. This neutral relay is so connected as to produce an impulse upon every reversal of line current. By use of this arrangement the corrections may be made utilizing simpler equipment than was used in the prior art. Furthermore, the neutral relay arrangement has operational characteristics which constitute a 'provide a neutral relay arrangement wherein the release time voi the neutral relay is used to produce a vcorrecting or synchronizing impulse.

It is a still further object of my invention to .provide an arrangement utilizing a neutral relay provided with a biasing winding in which the correcting impulse duration is vdetermined by the overlap period of a make before break 'contact adjustment on said relay.

Other objects and advantages of my invention will be apparent from the Vparticular description of my invention in connection with the accompanying drawing, 'in which Fig. 1 illustrates a schematic arrangement of a corrector circuit in accordance with my invention, and

- Fig. 2 discloses an alternative arrangement of ya corrector circuit utilizing the principles of my invention.

Turning first to Fig. 1, I show a main line relay Il provided with a contact armature arrangement !62. This main line relay operates to reproduce the received signals for transmission to the usual distributor segments for the received signals as well as for producing the corrector impulses. Since the signal portions of the distributor do not constitute a part of this invention, these features have not been illustrated. It is well known that in the usual multiplex line impulses of positive and negative current are utilized -in various groups to designate the sepa-rate characters. These signals are received over the line and serve to operate the polarized line yrelay lli l Operation of the line relay causes -a reversal of the connection of contact tongue H12 with ren spect to a local source indicatedat the upper par-t distinct improvement over the systems utilizing polar relays.

It is an object of my invention to provide a corrector system which is positive in operation and is simpler in construction than those known f in the prior art.

It is a further object of my invention to provide a correcting arrangement in which a neutral relay is utilized to generate the equivalent of the rectiiied first derivative of the line signals.

It is a further object of my invention to provide an arrangement which is independent of re lay bias and will function over a wide range of adjustments.

of the drawing by the plusk and minus sign. Accordingly each reversal of the line signal causes a reversal of polarityY of the current traversing winding m3 of relay..lt. yThis relay lllfi is a neutral relay and therefore each reversal of direction of the current causes the relay to release and reoperate. Upon each release of the v4relay its armature |05 closesa contact toground for the common ring Hlof correcting commutator Vl Ill. This circuit to ground is closed only momentarily 'since the relay its immediately reoperates breaking the ground contact. The time duration of the correcting impulse may be varied between 'predetermined limits by Iadjusting the tension of spring ist'. The usual printer relay may be inserted inthe lead 'of winding m3 at a suitable point, if desired. However, since'this particular arrangement forms no vpart-of my invention de- It is a still further object of my invention to 55 tailed illustration is omitted.

Commutator is provided with a common ring and a plurality of segments ||2 marked F and S in the drawing. These segments are alternately arranged and all of the F and S segments respectively, are separately connected together. A brush ||3 is provided to complete the circuit from the separate segments to the common ring, or may constitute the common grounded connection for the two halves of the commutator. A correcting relay |20, preferably a two-winding unbiased polarized relay, is provided, winding |2| of which is connected to the common lead of the S segment and through the winding |2| to a positive supply and winding |22 of which is connected from the common lead of the F segment through the winding |22 to the positive supply. Windings 2| and |22 are arranged so as to operate their common armature |23 respectively in opposite directions. For eX- ample, when a circuit is completed from positive battery through winding |22 contact F of distributor 0, brush ||3 and common ring contact to ground, the corrector relay armature 23 is moved to the position shown in the drawing. In this position a negative potential is applied through |23, the corrector switch |25, a meter |25 and winding |28 of correcting magnet |21 to ground. This energization of correcting magnet |21 serves to increase the speed of a tuning fork |30. The tuning fork is connected to control some suitable phase correcting means over leads |30. The increasedispeed of the tuning fork is preferably adjusted to drive the distributor at a speed slightly above the transmitting speed so that the distributor tends to gain with respect to the signals. The correcting means may be of any suitable type, for example a phonic wheel, but since the particular type of arrangement used constitutes no part of the invention these parts have not been specifically illustrated.

If, at the time relay |04 releases, the brush H3 is across atene of the S segments, a circuit is established from positive, winding |2| of relay |20, S segments, brush I3, contact |05 to ground. This connection serves to throw relay contact armature |23 to the right, opening the circuit of corrector magnet |28 to thus slow down the fork |30 and consequently reduce the speed of the distributor. 'I'he distributor will then tend to lag with respect to the received signals and will continue to slow down until it has reached such a position that the brush ||3 closes a contact through the F commutator segments, returning the contact armature 23 to the left position. The distributor then tends to slowly gain with respect to the received signals and the cycle is repeated. Since operation of the line relay determines the relative timing at which the distant sending distributor is passing from one segment to the next, each correction impulse developed by the neutral relay establishes the time at which the correction brush should be passing from an F to an S segment. Thus by using the circuit as'described above the phase of the distributor will be continually tested and the average speed will be held exactly equal to `that of the distant sending distributor.

In Fig. 2 is illustrated an alternative arrangement in accordance with my invention for utilizing a biased neutral relay to produce the correction action. In this iigure the parts of the circuit corresponding with those of Fig. 1 have been similarly numbered.

As fully described in connection with Fig. 1, the correction impulses are impressed by means of a commutator ||0 having segments marked F and S. Since the operation of the corrector circuit itself and the corrector magnet is the same as in Fig. 1, this portion of the circuit has not been fully illustrated and the operation of the system will not be described in detail. It is clear that the circuit of Fig. 2 may be used to replace the corresponding parts of the circuit in Fig. 1.

In this arrangement, however, I provide on relay |04 an additional biasing winding 20| and in place of the armature of the type shown in Fig. 1, I use with relay |04 an armature 205 in the form of a make before break switch. Also in Fig. 2 I have shown a connection through winding |03 of corrector relay |04 directly to the winding of the usual printer relay 20| 'I'his printer relay operates to repeat the received signals through to suitable printing apparatus or a transmitting distributor dependent upon the nature of the circuit with which the correcting means is associated.

Turning more speciiically to the details of the corrector control relay shown in Fig. 2, it will be noted that the connection of common ring ||l to ground must occur through the operation of armature 205 at the time that th'e ground contact 2 is made and before the circuit with contact has been broken. The correction impulse can only be developed when the armature 225 is properly adjusted to make one side before beraking the other and the duration of the impulse depends on the overlap time of 205. This can be varied by adjustment to produce impulses of sucient duration for satisfactory operation of the corrector relay. The biasing winding 20| in conjunction with negative potential through |02 serves to generally maintain armature 205 in the position illustrated. Upon change of polarity of thesignal by receipt of a positive signal impulse, armature |02 moves over to the positive side, and relay |04 will release since this added positive current is connected to oppose the biasing current. Upon the release of 2635 a contact is made with 2 before it is broken at During the short period of time that this condition exists an impulse is applied to the common ring of the commutator ||0. Switch 205 will then remain in the released position until another line signal of negative polarity arrives so as to again reverse the connection of contact |92. Upon reversing contact |02 to the negative side, relay |04 will again operate returning armature 295 to the left. As the armature 255 moves to the left contact is made before contact Z is broken and another correcting impulse is impressed on common ring of the corrector relay. It is thus clear that each reversal of the line current may serve to impress a correcting impulse through commutator H0 upon corrector relay |20. The nature of this correcting impulse will depend upon the speed of the distributor and its particular phase relation at the time the impulse is impressed. The time duration of the correcting signal may be adjusted by changing the period of overlap of make-beforebreak contacts 2535, and 2. Thus a control of the speed of the distributor to maintain itin substantial synchronism is produced as described more specifically in Vconnection with Fig. 1.

While I have disclosed particular arrangements of a corrector circuit to illustrate my in vention, it should be distinctly understood that these illustrated embodiments constitute merely a disclosure of certain preferred forms and should not be considered as deiining the scope of my invention. What I consider to be my invention and upon which I desire to secure protection is defined in the appended claims.

I claim:

1. A telegraph signal corrector circuit for systems using reverse polarity signals comprising a corrector relay, means controlled by said corrector relay for determining a speed, a commutator having segments connected to said corrector relay, means for completing a circuit between said segments and ground for operating said corrector relay comprising a neutral relay operative in response to each change in polarity of said signals, and contact means controlled by said relay for connecting said segments to ground.

2. A corrector circuit comprising means responsive to signal impulses for applying potentials of different polarity to a circuit, means in said circuit operative upon every change of polarity to alternatively release or to reclose dependent upon the applied polarity, and make-before-breal; means operative upon every release and every reclosure of said last named means for producing a correcting impulse of a predetermined time duration.

3. A telegraph system comprising a polarized line relay operative in response to received signals of different polarity, an armature moved by said line relay into one of two positions depending upon the polarity of said signals to connect current sources of different polarity thereto, a neutral relay having a Winding connected to said armature, and a polarized corrector relay operable by impulses from said neutral relay for applying speed correction.

4. A corrector system comprising a polarized line relay responsive to telegraph signals of different polarity, a biased neutral relay, means for energizing said relay with current the polarity of which depends on the nature of said telegraph signals in response to operation of said line relay, a corrector circuit and make-before-break contact means controlled by said biased neutral relay for applying a correcting impulse of predetermined duration to said corrector circuit in response to every change in polarity of said line signals.

5. In a correction circuit for a synchronously operating multiplex printing telegraph system, the combination of a line relay, a neutral relay controlled by said line relay to release and reoperate upon every operation of said line relay, a distributor comprising a plurality of correcting segments, a differential polarized correcting relay connected to said correcting segments, and means jointly operable by said neutral relay and said correcting segments for causing differential operation of said correcting relay.

6. In a correction circuit for a synchronously operating multiplex printing telegraph system, the combination of a line relay, a neutral relay controlled by said line relay to release and reoperate on every operation of said line relay to generate a series of impulses each of predetermined substantially equal time duration, a distributor comprising a plurality of correcting segments, a differential polarized correcting relay connected to said correcting segments, and means jointly operable by said neutral relay andsaid correcting segments for causing differential operation of said correcting relay.

7. In a correction circuit for a synchronously operating multiplex printing telegraph system, the combination of a line relay operating on incoming signals according to an equal element permutation code, a neutral relay controlled by said line relay to release and re-operate upon every operation of said line relay to generate a series of impulses each of a time duration equal to a fractional part of the unit elements of said incoming signals, a distributor comprising a plurality of correcting segments, a diierential polarized correcting relay connected to said correcting segments, and means jointly operable by said neutral relay and said correcting segments for causing diiferential operation of said correcting relay.

8. In a correction circuit for a synchronously operating multiplex printing telegraph System, the combination of a line relay, a neutral relay controlled by said line relay to release and re-operate upon every operation of said line relay, a distributor comprising a plurality of correcting segments and a common segment, means for applying ground to said common segment upon each release of said neutral relay, a polarized corrector relay having a first Winding connected to alternate ones of said correcting segments and a second Winding connected to the remaining correcting segments, means for driving said distributor, and a correcting brush driven by said driving means and effective jointly with said neutral relay to apply ground to one or the other Winding of said correcting relay in accordance With phase variations, and means under control of said correcting relay for increasing or diminishing the speed of operation of said driving means.

MARK B. KERR. 

